The printed proof is a simulation of the final output – a CMYK press sheet. The primary goal of proofing is to serve as a tool for customer verification that the entire job is accurate.  If errors are found during the printing process on press, correcting them can be very costly. A press proof usually serves as an agreement between customer and printer and as a color reference guide for adjusting the press before the final press run.

Digital Proofs and Press (wet) Proofs

There are mainly 2 types of proofs, the digital proofs and the press (wet) proofs.

The press proof, also called wet proof is the most accurate and costly proof both for four color and pantone color jobs. Wet proofs use the exact paper and inks to be used in the final job and therefore give an exact representation of the finished job. It requires special set-up on press and special plate output which makes it a pricier proofing option. However, this type of proofing process yields the best color proofing result.

The digital proof, sometimes also called color proof, provides the color-reliable/color-true reproduction of the contents of the file intended for printing. Color proofs are made with inkjet printers or thermal sublimation printers in combination with powerful color-management systems. Proofing is usually performed in full-size format, but in some cases small-page format is also acceptable. Color proofs serve as a guideline for a printing press operator.

Digital Proofs vs. Wet Proofs:

Advantages of Digital Proofs

The cost to output digital proofs is more competitive compared with wet proofs. Preparing digital proofs are faster than preparing wet proofs. There are fewer problems with dirt, spots, or registration problems which are common in wet proofing. Translating Digital proofs to Printed sheets: digital proofs are warmer than wet proofs because of the nature of chemical ink–it is different from actual printing ink. The color tolerance between digital proofs against the press sheet is about 10%.

Disadvantages of Digital Proofs

Digital proofs do not reveal problems in the files, such as trapping, overprints, or moirés. The tint colors in digital proofs cannot be matched during actual printing. PMS (Pantone matching system) colors are not as accurate in digital proofing as it is in wet proofing.

Advantages of Wet proofs from CTP Plates

The cost to output wet proofs is more economical if several sets of proofs are needed. The color is more accurate for black and white, duotone, and 4-color black and white images or for PMS colors. Problems in the files will be apparent, such as trapping, overprints, and or moirés. Wet proofs use the same paper type and weight as it will be used during manufacturing.

 Disadvantages of Wet proofs from CTP Plates

Wet proofs take longer to prepare than digital proofs. Dirt, spots, and registration problems cannot be avoided. The cost of outputting wet proofs are high if only one or two sets of proofs are needed.